A typical large truck comprises axle assemblies on which wheels are mounted. At its opposite ends, a typical front axle assembly comprises steerable shafts, or spindles, and hubs journaled for rotation on the shafts, or spindles. The hubs have circular patterns of outwardly protruding screw studs, or lugs, that match circular bolt hole patterns in the hubs of the wheels to allow the wheels to be placed onto the axle hubs with the lugs on the axle hubs protruding through the holes of the bolt hole patterns in the wheel hubs. Lug nuts are then threaded onto ends of the lugs and tightened to force the wheel hubs against the faces of the axle hubs thereby securing the wheels to the axle hubs.
The construction of mass-produced axle assemblies inherently results in some axial end play of the axle hubs on the axle shafts, and because wheels are fastened to the axle hubs, the wheels will have also have endplay on the axles. While a limited amount of endplay may be acceptable, excessive endplay is undesirable for various and obvious reasons.
Consequently, measurement of such endplay is an important part of quality control in a manufacturing process.
Prior to the present invention, a manual method that uses a dial indicator was one method for measuring axial endplay between the hub and shaft. The hub is pushed and pulled by paddles, and the dial indicator measures axial movement of the hub relative to the end of the axle shaft. Accuracy and repeatability of the measurements obtained by the manual method are subject to human influences by the very nature of the method.
Another prior method involves use of a measuring tool having a pneumatic actuator for pulling the hub via the hub cap mounting holes. But that tool has to be manually installed and removed, and its installation, use, and removal are considered difficult and time-consuming.
Consequently, it is believed that a method that is less subject to human influences would be a desirable improvement, especially in view of increased emphasis on manufacturing quality.
In addition, a tool that is easier and quicker to install, use, and remove would be desirable for improving productivity in a manufacturing facility.